PHP+MYSQL執行個體：網站線上人數的程式碼

PHP執行個體教程：網站線上人數的程式碼，後台有MYSQL資料庫支援。可以直接統計出網站當前的線上人數。

首先是建立MYSQL資料庫表。

以下為引用的內容： CREATE TABLE tablename ( field type(max_length) DEFAULT 'default_value' (NOT) NULL }

可以使用的SQL語句。

以下為引用的內容： CREATE TABLE useronline ( timestamp int(15) DEFAULT '0' NOT NULL, ip varchar(40) NOT NULL, file varchar(100) NOT NULL, PRIMARY KEY (timestamp), KEY ip (ip), KEY file (file) );

下面我們開始使用PHP指令碼，首先定義MYSQL的資訊。

$server = "localhost"; //你的伺服器

$db_user = "root"; //你的mysql的使用者名稱

$db_pass = "password"; //你的mysql的密碼

$database = "users"; //表的名字

設定統計的時間(多少秒內線上人數)

$timeoutseconds = 300;

取目前時間。

$timestamp = time();

上面的完整代碼：

以下為引用的內容： $insert = mysql_db_query($database, "INSERT INTO useronline VALUES ('$timestamp','".$_SERVER['REMOTE_ADDR']."','".$_SERVER['PHP_SELF']."')");

串連mysql

mysql_connect('localhost', 'username', 'password');

也允許使用變數形式。

mysql_connect($server, $db_user, $db_pass);

如果mysql資料庫沒有密碼的話可以使用下面代碼串連（當然建議大家一定要設定好自己的密碼，這樣起碼駭客得要解密啊）

mysql_connect($server, $db_user);

查詢資料庫的代碼：

mysql_db_query('database', 'query');

我們只要有訪客就要增加一條記錄。

以下為引用的內容： $insert = mysql_db_query($database, "INSERT INTO useronline VALUES ('$timestamp','".$_SERVER['REMOTE_ADDR']."','".$_SERVER['PHP_SELF']."')");

然後我們給出如果使用者用錯誤資訊的處理方式。

以下為引用的內容： if(!($insert)) { print "Useronline Insert Failed > "; }

然後我們得實現當超過我們設定的時間我們就要刪除該使用者記錄。

$delete = mysql_db_query($database, "DELETE FROM useronline WHERE timestamp<$timeout");

同樣給出刪除記錄出錯的處理。

以下為引用的內容： if(!($delete)) { print "Useronline Delete Failed > "; }

下面我們顯示資料庫中有多少個不同的IP

$result = mysql_db_query($database, "SELECT DISTINCT ip FROM useronline WHERE file='".$_SERVER['PHP_SELF']."' ");

我們使用

mysql_num_rows(query);

來統計使用者，代碼如下。

$user = mysql_num_rows($result);

最後我們要關閉資料庫。

mysql_close();

顯示線上的人數。

以下為引用的內容： if($user == 1) { print("1 user online\n"); } else { print("$user users online\n"); }

最終把上面代碼寫成一個PHP檔案如下。

以下為引用的內容： <?php //Put your basic server info here $server = "localhost"; //normally localhost $db_user = "root"; //your MySQL database username $db_pass = "password"; //your MySQL database password $database = "users"; $timeoutseconds = 300; //it will delete all people which haven't refreshed(so probbably are // offline or inactive) in $timieoutseconds time (so it actually checks the people that are active in the last // $timeoutseconds seconds) //this is where PHP gets the time $timestamp = time(); //counts the timeout, all people which have been seen last online in earlier than this timestamp, will get removed $timeout = $timestamp-$timeoutseconds; //connect to database mysql_connect($server, $db_user); //add the timestamp from the user to the online list $insert = mysql_db_query($database, "INSERT INTO useronline VALUES ('$timestamp','".$_SERVER['REMOTE_ADDR']."','".$_SERVER['PHP_SELF']."')"); if(!($insert)) { print "Useronline Insert Failed > "; } //delete the peoples which haven't been online/active in the last $timeoutseconds seconds. $delete = mysql_db_query($database, "DELETE FROM useronline WHERE timestamp<$timeout"); if(!($delete)) { print "Useronline Delete Failed > "; } //select the amount of people online, all uniques, which are online on THIS page $result = mysql_db_query($database, "SELECT DISTINCT ip FROM useronline WHERE file='".$_SERVER['PHP_SELF']."' "); if(!($result)) { print "Useronline Select Error > "; } //Count the number of rows = the number of people online $user = mysql_num_rows($result); //spit out the results mysql_close(); if($user == 1) { print("1 user online\n"); } else { print("$user users online\n"); } ?>